The Duke of Cambridge has called on councils to secure the long-term future of memorial parks honouring Britain's war dead on his first public engagement as president of the Fields in Trust (FiT) charity.

William was visiting Coventry's War Memorial Park today which is the first green space in the country to be dedicated as part of the charity's Centenary Fields programme.

The programme, run in partnership with the Royal British Legion, is working to secure the future of Britain's memorial parks as part of a living remembrance for the country's war dead, in the centenary year of the start of the First World War.

The Duke, who placed a wreath at the garden's centrepiece memorial during his visit, said these green spaces should not be taken for granted, describing them as "a vital part of our national heritage".

He added: "Each moment of play or use that takes place on a memorial field is, in a way, an act of remembrance."

William praised Coventry City Council's leading example and said FiT would now "encourage and cajole" councils across the country to secure the future of similar parks in their areas.

"I have no doubt that they will succeed, but only if they have help," he added.

The Duke was greeted by hundreds of people as he made his way towards the towering stone memorial to the 2,587 men of the city killed in the Great War, which dominates one end of the park.

He spent a moment chatting with two veterans of Britain's post-colonial counter-insurgency in Borneo in the 1960s, ex-paratroopers Lonnie Downes and Mick Murtagh.

William also took time to shake hands with members of the public who had crowded the large park for a glimpse of the royal heir.

There was also time to pause and reflect as he then laid a poppy wreath at the base of the memorial, which was first dedicated by Field Marshal Earl Haig in 1927.

Outside, he met 90-year-old Freda Jones who was just three when her father - company sergeant major Arthur Russell of The Royal Warwickshire Regiment - was part of the guard of honour who met Earl Haig that day.

After meeting William, a tearful Mrs Jones said she had recounted how he had looked as a young baby: "I told him he looked beautiful.

"He was lovely, and I told him he was lovely and he just smiled and held my hand."

Cheered wherever he went, the Duke then showed he may have more than a little of his father's green-fingered talents, helping a class of pupils from the city's Howes Primary School plant poppy seeds near the park's play area.

With the aid of Royal British Legion's learning packs, the school's children have been learning about the history of the First World War and the important symbolism of the poppy which serves as a reminder of those killed in action.

William seemed at ease chatting with the youngsters as he upended a bag of seeds into a hole he had scooped out in the soil before praising the efforts of a pupil standing next to him, saying: "Good job!".

Also charmed by the Duke were pupils Phoebe Marriott and Eloise Smith, both nine, who said: "He was quite funny.

"We haven't met any royalty before - but we had a nice time."

William was then put through his paces on the nearby tennis court by another group of school children and just seemed to be getting into his stride before he had to move on.

He then waved the starting flag on a school sports day taking place in another area of the park, before handing out the medals for those taking part.

Before unveiling a plaque marking the first of Britain's Centenary Fields, the Duke said the First World War "continues to inspire us, 100 years on, to undertake acts of remembrance for men and women otherwise long forgotten."

Referring to the country's "countless memorials", he said none were more ambitious than those areas set aside "as spaces of remembrance" , and it was important that these places existed "where freedom may be expressed with such ease".

"This War Memorial Park in Coventry has to be one of the most extraordinary examples of this," he added.

"The stunning war memorial, and the many other memorials around the park, are dotted between places where children play football and throw Frisbees, families picnic together, or walk the dog.

"It is a beautiful place - Coventry City Council and the people it serves have every right to be immensely proud of it."

He said: "The Centenary Fields project, which I am privileged to launch today, aims to save in perpetuity scores of memorial spaces around the country.

"Most will not be as large as this, but every one is valued by its community."

Calling on councils to play their part, William said: "I encourage local authorities to support this cause and to safeguard these living spaces of remembrance for generations to come."

The Duke took on the role of FiT president in April 2013, following the retirement of his grandfather, the Duke of Edinburgh, who held the position for 64 years.

William was also patron of the Queen Elizabeth II Fields Challenge which safeguarded parks and open spaces to mark the Queen's Diamond Jubilee, in 2012.

The programme will mean that parks and open spaces designated as Centenary Fields are protected against possible future development such as house-building.

Royal British Legion national chairman John Crisford said: "Our partnership with FiT ensures we are helping to preserve these important memorials, often found in community spaces that form a vital part of local heritage and play a key role in educating the next generation about the significance of remembrance."

Tim Phillips, who is chairman of FiT, said: "This programme is a fitting way for us to mark the sacrifices made by so many in World War One whilst looking to the future through a living remembrance.

"We look forward to working with the Royal British Legion to preserve valuable green spaces for local communities in partnership and hope that hundreds of local authorities will follow in Coventry City Council's footsteps and join us in this initiative."

Meanwhile, city councillor Abdul Khan said Coventry was honoured to have hosted the Duke.

"In Coventry we are proud of our international reputation as a city of peace and reconciliation and we are determined those who lost their lives in conflict are never forgotten," he added.